Tumor-DerivedIL-1β Promotes Adhesion of Vascular Endothelial Cells with Hepatoma Cells Through NF-κB p65 Signaling Pathway / 华中科技大学学报(医学版)

ABSTRACT

Objective To elucidate the effect of tumor-derived interleukin-1 beta(IL-1β)on adhesion of vascular endothelial cells(HUVECs)with hepatoma cells and the potential molecular mechanisms. Methods HepG2 cell line stably expressing IL-1β(HepG2/IL-1β)and GFP(HepG2/GFP)was established by lentivirus transfection,and the IL-1β in cell culture supernatant was determined by ELISA. Conditioned medium(CM)containing IL-1β(IL-1β-CM)of HepG2 cells was used as a source for tumor-derived IL-1β,and was controlled with CM from HepG2/GFP cells(Ctrl-CM). HUVECs stimulated with 10 ng/mLIL-1β(HUVECs+IL-1β-CM)were used to observe their adhesion ability with HepG2/IL-1βand HepG2/GFP cells,and HUVECs+CtrlCM served as control. The mRNA expression levels of E-selectin(CD62E) ,ICAM-1(CD54)and VCAM-1(CD106)in HUVECs were detected byqRT-PCR. Cell surface expression levels of CD62Eand CD54 were detected by flow cytometry.IL-1β induced signaling pathways in HUVECs were analyzed through Western blotting. Specific inhibitors were usedto block each signaling pathway,and the expression of adhesion molecules as well as the adhesion of vascular endothelial cells with hepatoma cells were subsequently monitored. Results Tumor-derived IL-1β significantly enhanced the adhesion of HUVECs with HepG2 cells and upregulated the expression levels of CD62E and CD54 mRNAin HUVECs cells. The surface CD62E was temporarily upregulated 4 h after IL-1β stimulation,while the expression of CD54 protein showed a continuous upregulated pattern,which lasted from 4 hto 24 h.IL-1β mainly activated NF-κB p65 and p38 MAPK signaling pathways in HUVECs,and NF-κB p65 was proved to be located at upstream,regulating the activation of p38 MAPK pathway. Targeted blocking of NF-κB p65 pathway by specific inhibitor significantly downregulated the expression of CD62E and CD54 on surface of HUVECs and inhibited their adhesionability with HepG2cells. Conclusion Tumor-derived IL-1β promotes adhesion of HUVECs with hepatoma cells through upregulation of CD62E and CD54 expression by activating NF-κB p65 signaling pathway in HUVECs. Tumor-derivedIL-1β might be involved in invasion and metastasis of hepatoma cells through vascular system.